New Knowledge of the Ear's Hidden Susceptibility to Hearing Loss and the Magic Formula for Predicting SNR Loss

Mead Killion

A method for predicting the difficulty of understanding speech in noise, quantified by the measured Signal-to-Noise Ratio loss will be presented. By incorporating an estimate of the loss of inner hair cells or neural terminals, the performance of someone with hearing loss can be predicted over a wide range of real-world conditions, and using the "magic formula" the complete curves describing intelligibility of digits, sentences, words in sentences, and NU 6 words in noise can be predicted from one point. Next, a simple two-minute test for dead zones in the cochlea will be described, along with the "pitch diplacusis" which prevented Yehudi Menuhin from playing the violin in later years. A recent experimental "bridging" of a dead zone for one musician made it possible for him to play in tune again. Finally, a DVD showing a high school drum line will be provided each attendee. In addition to showing the 14x allowable unprotected dose its players would experience without hearing protection, it includes comments from professional musicians after years of exposure.